Fuel-pump for internal-combustion engines.



A. HQ'HOADLEY. V FUEL PUMP FOR INTERNAL COMBUSTION ENGINES.

APPLICATION FILED DEC. 22, 1911. 4 1,080,216. v Patented Dec. 2, 191 3.

2 SHEETSSHEET 1.

W/TNESSES: INVENTOR ATTORNEY.

A. H. HOADLEY. FUEL PUMP FOR INTERNAL COMBUSTION ENGINES;

APPLICATION FILED DEC. 22, 1911;

Patented Dec. 2, 1913.

2 SHEETSSHEET 2 W t w o? m A m Arm!) n. noanmr, or rnovrnnnca-nnoneISLAND.

FUEL-PUMP FOB INTERNAL-COMBUSTION ENGINES.

Specification of Letters Patent;

Patented cc. 2, i913.

Application filed December 22, 1911. Serial No. 687,281.

To all whom it may concern:

Be it knownthat I, ALFRED H. HOADLEY,

a citizen of the United States, residing at pressure superior to thepressure of compression. This may be accomplished by the pump injectingthe liquid fuel directly into the compressed charge of air in thecombustion cyllnder, or into an auxiliary charge of air of superiorpressure, which in turn injects the mixture of fuel and air into thecylinder. It is this class of pump to which my invention moreparticularly applies, the object of my invention being primarily, toimprove upon the apparatus heretoforedn use for this purpose, and toprovide a simple and eflicient mechanism, comprising a combination ofmembers, organized forgpperating with practical economy in expense andcost of maintenance. Also, to attain a bet-- ter operation and results,and an improvement in the means of governing the speed of the enginethrough the operatlon of the improved pump.

My invention pertains more es ecia lly to multiple-pumps, although someeatures of my improvementsmay be applied to pumps used to serve asingle-cylinder engine.

Engines of the type named have heretofore, 1n some instances, beenregulated in speed by varying the amount of the liquid fuel injectedinto the cylinder at each working stroke. The totalamount of the fuel isalways relatively small, while the variation in amount, due to smallchanges in load, is extremely small. Itis therefore desirable that thepump should becap'able'of a positive and variable delivery of minuteamounts, and against relatively heavy pressures. It

I would seem that a properly designed heavypnes'su-re pum having avariable-stroke plunger, varia le from zero to maximum stroke by theaction of a governor, would accomplish this end; but such a pump has.'been found, in practice, to fail to deliver reliably at the shorterranges of its'stroke. The most successful type of pump for this serviceis one having a constant, maximumstroke plunger with a variable by-passwhich shunts a portion of the pump delivery back into the suction pipeand closing the pass at that point in the stroke which represents therequired delivery due to the remainder of the stroke. One application ofthe above named by-pass principle is to use the suction-valve as aby-pass, employing in connection with the valve, means controlled by thegovernor for holding the valve open during a part of the deliverystroke, whereby the fuel will flow back into the suction pipe instead ofbeing delivered against a superior pressure, until the suction-valvecloses whereuponthe delivery due to any uncoma pleted portion of thedelivery stroke of the plunger, will take place. My invention appliesequally Well to pumps having either the delivery by-pass or thesuction-valve variable closing system.

Heretofore, for multi-cylinder engines, it

has been customary to employ a completepump for each cylinder; that is,having a separate plunger, connections and operating details, for everycylinder, in order to insure positive and unvarying results. VVhlle suchpractice is efl'ective as to results, it becomes expensive in engines oftwo or three cyl nders, while in case of four, six or eight cylinders,(or even more as promise to obtain in marine units,) the cost becomesexcessive, especially in high-pressure engines where the umps mustdeliver against a; ressure of Eve hundred pounds or more. y inventionprovides a simplified construction and novel mechanism, requiring butone pump to supply two or more cylinders, the single ump being timed asto speed to give a de ivery stroke of the plunger for each firing,stroke of each cylinder; and combined with the pump casing'is a systemof delivery passages and valves, one for each cylinder. These valves arecontrolled and timed in operating so as to deliver the pump discharge inrequired quantity to the proper one of the several cvlinders at theproper time. An essential element in the combination is a bypass valve,which can-.be arranged for operating in either of the ways abovementioned.

" thereto determined by the number of cylinone by-pass will su ce;whereas heretofore suction-valve; but it will be-understood that view ofthe same taken on the line A B, and in a plane at right angles toFig. 1. Fig.

engine-shaft at a speed ratio to the shaft 7 that severally permitdischarge into secondary passages or spaces 8; each opening liquid tot ecylinders. (Not herein shown.)

To serve sa four 0 lindersione um and a separate and complete pump andcomplete by-pass devices were required for each and every cylinder.

To illustrate the nature of my invention, I have shown, in theaccompanying drawing, an embodiment thereof adapted to serve athree-cylinder engine, and a form wherein the by-pass function isperformed by the my invention is applicable for any other number ofcylinders, and is equally Well illustrated by the drawings as the properelements for any additional number of cylinders would be combined andarranged to operate substantially like those here shown.

I do not limit myself to the exact details or to the precise arrangementof parts as shown; the illustration being typical in character, andvarious modificatlons can be made from the form shown and still embodymy invention.

In the drawings, Figure 1 is a partly sectional elevation view showingthe elements which are essential to my invention, together with suchother parts as will pertain to a complete working pump of the characterclaimed. Fig. 2 is a fragmentary sectional 3 is a horizontal sect-ion atline X on Fig. 1, and Fig. 4 is an end view of the slidable regulatingcam whereby governor control is transmitted to valving means. Fig. 5 isa sectional detail view at line Y Y, of one of the check valve fittingsfor the cylinder ducts or delivering passages, and Fig. 6 is afragmentary section showing a modification in the by-pass means.

In the construction shown the numeral 1 indicates arotatable shaft,serving as the motor shaft for the parts shown, and which in practice isdriven by connection with the 'which must bear a certain speed relationdots in the engine. An eccentric 2 fixed upon shaft 1 is connected tooperate the reciprocating pump-plunger 3. This works in the (pumpchamber 4 within the casing or body ofthe pump, and into which a suc-vtlon passage 5 debouches, and out of which a delivery passage 6 leads.Said passage 6 is provided with exits or delivery openings 7 beingcontrolled by a delivery valve 9. There must be a separate exit assagefor each engine cylinder to be servedfeach passage being independent ofthe others beyond the delivery controllin valve. Leading out of theexits or secon ary passages 8 are ducts or 'ipes 10, which deliver thefuel one-third the speed. It may ratus and communicate with thesecondary passages 8 by means of fittings 11, which are adapted to veryhigh ressure, in this instance, and each contains a double checkvalvedevice 80, of a proved kind, to prevent return of any of the fuel liquidafter entering the duct.

The delivery valves 9 have stems 90, and are individually opened by cams12 carried on the shaft 13. In the present instance the valves areassistedin closing by springs 14. The cam-shaft 13 may be driven fromthe shaft 1 by spur gears 15 and 16, or otherwise. The manner of drivingis unimportant so long as the rotation is positive and the speed-ratiocorrect. This ratio must be as the number of cylinders is to onerevolution of shaft- 1, in this case three to one. The series of cams12, 12, 12, are designed and arranged to. time in succession,corresponding with an entire delivery stroke of the plunger 3. It willtherefore be understood that with the aforesaid speed ratio, threesuccessive delivery strokes of the pump will discharge fuel successivelyinto the three cylinders, as determined by the series of controllingcams 12, 'ving in the engine the same effect as to time and charges aswould three individual pumps, 0 crating at e further noted that in anyinstance the speed of the single pump must be such as to give onerevolution of the plunger-driving shaft 1 to each firing stroke of theengine.-

My improved governing means consists of the combination of parts shownat the right-hand end of Fig. 1. Upon the shaft 1 is mounted a slidablecam 17 which is caused to rotate with the shaft by a spline 1 and isactuated by endwise movement 0 en one delivery at a to open period ofeach from the engine governor G through any ber 91, that is moved byfluctuations of the governor element; which latter can be of anyapproved kind. The fuel, from a suitable source of supply, is deliveredby H.'

In this in- Y .nected by the link 19 with a lever, or mem-' pipe 20 intoasecondary chamber 21 and 4 from there it passes in'tothe suctionpassage 5 through the opening 22 controlled by the suction-valve 23,(Fig. 1) which valve is carried upon a stem 23 arranged through asuitable packing-gland and guide bearing, and is best provided with aroller 24 at 1ts end, against which the cam 17 acts.

The

cam 17 is so formed that for one-half of its revolution it does not'liftthe suction-valve at all, which is free to act in a normal manno liftingis pump-plunger. The other half of the cam is formed to effect avariable lift action on the suction-valve during the delivery stroke ofthe pump, by its protuberant portion 71 acting upon the roller 24 in t eend of the suction valve-stem. When the cam' is at one, end of itssliding stroke with the small end under the roller 24', iven to thesuction-valve by said cam uring the deliver stroke of the pum plunger 3.Hence t e entire volume of ischarge for that stroke of the pump must goto one or the other of the cylinders. ,On the other hand, when the camis at the other end of its slide-stroke with the large end of the cambeneath the roller 24, then the suction-valve will be lifted and heldopen during the entire discharge stroke of the pump, thus serving as aby-pa ss and consequently the fluid will all be pushed back into thesuction pipe on account of the lesser pressure in that direction, andthere will be no discharge'whatever to either cylinder. In anyintermediate position of the cam 17 there will be a corresponding partof the delivery-stroke, during'which the suction-valve will be held openand a part of the discharge will go back into the suction- .pipe; while,upon the closing of thesuctionvalve 23, that part of the discharge dueto the remaining portion of the plunger stroke, will be forced into oneor the other of the cylinders. Thus it will be seen that thesuction-valve opens freely to admit the suction of fuel into the pumpingchamber;-but its closing action is mechanically regulated by theposition of the cam 17 which is determined by the governor (Jr. Hencethe regulation of the quantity of fuel that is sent to a cylinder isvery accurately adjusted to the requirements. for a properlyproportioned charge. This same mechanism will work equally well ifapplied to a separate by-pass, or by-pass-valve for the pump discharge,an example of' which is illustrated in Fig. 6, wherein a separate orspecial by-pass conduit 33 is provided and the controlled valve 34 isarranged in said special conduit; the valve stem 34* being actuated bythe cam 17. A valve closing spring 36, having atension power superior tothe suction force exerted on the valve, is best combined with the valvestem, as indicated. If desired; this by-pass can be connected with thedischarge side of the pump and lead back to the supply pipe 20, theoperatingefi'ect being practically the same as above explained. In thismodification there must bean independent suction-valve 32 in addition tothe byass valve 34, and aseparate passage from t e suction pipe must beprovided therefor. x

I do not claim broadly, aduating the discharge of. a pump, either y thesuctionvalve method or the by-pass method; my invention and claim havinreference to a particular way or manner 0 operating a by-pass or asuction-valve whereby increased sensitiveness of governing is obtained,a more eilicient action of the fuel supplying means secured; and theregulation of speed and action of the engine is im roved. In mymechanism the cam 17, which has onl one valve to operate, is subjectedto practically no longitudinal thrust from the resistance of lifting thevalve, what little thrust there may be, not 'being enough to overcomethe sliding friction of the cam on the shaft, consequently theresistance to be overcome by the governor is only this sliding friction,which is very small and which is also a constant resistance. During fromone half to about nine tenths, of a revolution of the cam, practicallyno Work is being done on the roller 24 by the cam. Hence the governorhas this time to shift the cam practically without any resistance, andwithout any disturbance when the cam lifts the valve, whatever degree ofpressure the valve may have to open against. The result is that thegoverning of the discharge will be as close as the governor is capableof producing, and untra-mmeled by undue and variable disturbances.

The effect of my herein described improvements and of their applicationto an internal combustion engine, is to equalize the intensity of thefiring and enhance the efliciencyin the regulation whereby smoothness ofoperation is attained and wear and tear is reduced, which advantages areadditional to the reduction in the original cost of construction of thefuel pumping mechanism, as hereinbefore set forth.

I claim- 1. In an apparatus for supplyingliquid fuel to the cylinders ofan internal combustionengine, the combination of a unitary pump having aprimal discharge chamber with a plurality of exits, operateddeliveryvalves including an independently acting valve for each of saidexits, a freely operable mechanically controlled suction valve, meanscomprising a positively driven cam-shaft with a series of cams thereondisposed to severally operate said delivery valves, and means forvarying the closing action of said suction valve working, synchronouslywith the pump.-

2. In an apparatus for supplying liquid fuel to the cylinders of aninternal combustion engine, the combination of a single plunger pumphaving a plurality of delivery exit passages, individual conduitstherefrom for the respective cylinders, aseries of independently movablevalves for the deliveryexit passages, mechanically actuated .means foroperating said deliverywalves, a bypass valve controlling a by-passlocated between the supply conduit and pum -chamsuction valve, and meansfor operatin said by-pass valve, for the purpose specific 3. In a fuelpump for internal combustion engines, the combination, of a pump bodyincluding a passage, and a de ivery passage, a pumpmg plunger working insaid pumpchamber, a plurality of separate valve-controlled openings intounderlying secondary passages that communicate by a separate feed-ductwith the engine cylinders, a controlling puppet-valve for each of saidopenings into the secondary passages, said valves having end- -wisereciprocating stems at the exterior of the casing, and means comprisinga rotatin cam-shaft with a series of cams carrie thereon, forindividually operating said valves. V

4. In mechanism for forcing liquid fuel into cylinders ofmulti-cylindrical internal combustion engines, the combination of a pumpbody including a pump-chamber having a suction-passage anddischarge-passage connected therewith, a supply conduit with a portopening into said suction passage, a plurality of exit ports openingfrom said discharge passage, with secondary passages and fittings forattaching the several cylinder supply pipes, individual valves for therespective inlet and exit ports, each having a projecting stem, a singlepumping element working in said pump chamber, a rotating shaft havingmeans for reciprocating the pumping element, a supplemental shaft havingmeans for individually opening said exitvalves, gearing operating saidsupplemental shaft at a speed ratio as the number of exit valves is toone stroke of the pump, an endwise movable cam acting against the stemof said inlet valve,. and means for varying the relative position ofsaid cam in accordance with the speed of rotation of the motorshaft.

5. In a fuel-supply mechanism for multicylinder internal combustionengines, the

ump-chamber, a suction combination of a pump casing including a chamberhaving a laterally extended area provided with a plurality ofvalve-seated egress openings and secondary separate chambers beneathsaid openings, a pumping element adapted for working therein withitsstrokes synchronous with the firing intervals of the series ofcylinders-,-means for actuating said pumping element, an ingress passageto said chamber, a plurality of separately actuated egress valves, ductsfor taking the discharge from the individual second- 'ary chambers tothe respective engine cylinders, said ducts provided with automaticaLlyact-ing check-valves, a rotating shaft actuated by positive gearing inconjunction with the actuating means for the pumping discharge passages,each provided with an independently acting closing valve having aprojecting valve stem, individual conduits from said discharge passagesfor connecting the respective engine cylinders, said conduits havingmeans for preventing back ward flow therein, a revoluble cam shaftcarrying a series of cams that individually actuate saiddischarge-valves in sequence, means for rotating said cam shaft at aspeed ratio greater than pumping impulses.

Witness my hand this 20th day of December, 1911.

, ALFRED H. HOADLEY.

Witnesses:

GEORGE P. MACREADY, WILLIAM E. WHITE.

